a physical visualization curtain made of human figures & abstract plus signs, which reacts to mobile phone activities (like a phone call, SMS messages, etc.) in its vicinity. when this happens, the cloud comes alive with streams of light flowing between the objects. the objects glow & dim: a human figure, a plus sign, another human figure, another plus sign & so on. an imaginary line is created, portraying a trajectory of a phone call. see also light curtain & bitfall water curtain. [tiltool.com|via we-make-money-not-art.com]